Question 369873
Convert the kitchen measurements to inches and find the total area of the kitchen.
{{{12*12+8=144+8=152}}}inches
{{{17*12+9=204+9=213}}}inches
{{{A=152*213=32376}}}sq.inches
Each tile has an area of 
{{{A[t]=8*8=64}}}sq. inches.
So then,
{{{N=A/A[t]=32376/64=505.9}}} 
Round up to {{{N=509}}} but you should always purchase 10% more in case of mistakes or mismeasurement.